Investigating Glyphosate Resistance
University of Maryland Researchers May Know Why

Giant ragweed (Ambrosia trifida), a member of the sunflower family is native to North America. It is considered a noxious weed in its native range.
Credit: Robert H. Mohlenbrock, hosted by the USDA-NRCS PLANTS Database / USDA SCS. 1989. Midwest wetland flora: Field office illustrated guide to plant species. Midwest National Technical Center, Lincoln.

Assistant professor Burkhard Schulz of the University of Maryland's Plant Science and Landscape Architecture department recently wrapped up a research project to determine the mechanism and cause of glyphosate resistance in giant ragweed.

The research team concluded that the weed detoxifies the herbicide, which then prompts a regrowth of giant ragweed and the subsequent choking out of desired plants.

Next, Schulz is looking to disarm the defense system that enables the weed's survival after a toxic dose of RoundUp, with the ultimate goal of making giant ragweed once again susceptible to the herbicide. Once accomplished, the knowledge can be applied to other resistant plants.

The full study was published in the journal Pest Management Science. Collaborators included researchers from Colorado State University, USDA, Purdue, Oregon State University, University of Guelph, Washington University and Monsanto.